Depicting Shimmer, Shine, and Iridescence
German 13th Century, The Triumph of the Church, second half 13th century, tempera and gold leaf on vellum, National Gallery of Art, Washington, Rosenwald Collection, 1959.16.1
Color is our perception of light, and artists somehow work in the inverted color spaces of reflection and absorption: one irreal, the other often simply paint. Artists’ renditions of the lit world and representations of its animate, changeable qualities—using nothing more than pigments in various vehicles—are astounding. My time at the Center, all too brief and defocused, was spent searching for clues on how artists experimented in order to depict luster and sheen, exploiting materials’ inherent visual and physical properties. My intent was to build on prior work on how and when artists used glassy material in paint. I had aimed to travel to Amsterdam to analyze “chemical glasses” found in a collector’s cabinet with a miniature apothecary (Rijksmusem, BK-1956-44) and to pore through the archives looking for hints about links between pigments and glassmaking. Hardly leaving my office, let alone Washington, owing to travel restrictions, changed the tenor and focus of my fellowship such that my project title no longer reflects the lines of thinking that emerged.
In the early modern era, artists’ and commentators’ descriptions of the colors and properties of pigments are usually spare. One useful exception is Gian Paolo Lomazzo’s description of l’oropimento arso, burnt orpiment, which follows from how to paint orange. Burnt orpiment is said to be the color of gold and considered the alchemy of Venetian painters. It was, however, reviled on account of its toxicity, obnoxious smell, and apparent tendency to darken. Authors from Cennino Cennini (c. 1370–c. 1440) to Nicholas Hilliard (probably 1547–1619), myriad house painters’ guides, and compendiums of advice warn against using orpiment although it is a brilliant yellow, the color of daffodils and primroses. In fact, large particles of orpiment are glittery—an observation that caught my eye. I reviewed analytical reports in the files of the scientific research department, searching for results suggesting that artists had used orpiment. In one, the analyst, Lisha Glinsman, recorded her observation that the yellow particles in a painting’s heraldic device appeared “somewhat sparkly.” The particles are not shell gold, nor mosaic gold; they most likely are orpiment. Orpiment is also found in an English miniature painting, depicting tiny links of gold chains adorning the sitter.
But what of the glassy pigments? I found no additional textual descriptions of glass in painting manuals or treatises. In “Venetian Glass and Renaissance Self-Fashioning,” Paul Hills writes that, in the Middle Ages, the “claritas of lustre, particularly gold, outshone the claritas of transparency.” My sense is that the diffuse reflection of light rather than its muted transmission prevails on the artist’s mind, perhaps even today, because this is the way paint works: we see light reflected from it. I am compiling circumstantial evidence from texts and published chemical analyses that artists do, in fact, try out specific, new materials and techniques in order to represent and express the ineffable colors of translucent, glowing skin, metallic sheen, iridescent feathers, and evanescent rainbows.
Whites made from shells are mentioned in a few texts as difficult to manufacture and procure, but authors argue that their special qualities make them worth seeking out. Since the whites made from the inner parts of oyster shells were hard to find, one anonymous author (Miniature Painting, 1731) recommended using lead white treated with vinegar for highlights. This suggests searching for cerussite in paintings, especially works on paper. Bismuth oxychloride, named Pearl White, a nod to its nacreous sheen, is also found in Edgar Degas’s wax Study in the Nude of Little Dancer Aged Fourteen (Nude Little Dancer).
I will give my last words to Chang Yen-yüan, a mid-ninth-century Chinese writer, who said: “Mountains are green without needing malachite, and the phoenix is iridescent without the aid of the five colors. . . . If one’s mind dwells on the five colors, then the images of things will go wrong.” This fellowship offered me an opportunity to think about more than glass and to consider the role of other pigments in capturing the ways we see light.
National Gallery of Art, Department of Scientific Research
Ailsa Mellon Bruce National Gallery of Art Sabbatical Fellow, 2021–2022
Barbara H. Berrie returns to the Department of Scientific Research at the National Gallery of Art, where she is head of the department and a senior conservation scientist.
